Portland State University. Department of Physics
Date of Award
Master of Science (M.S.) in Physics
1 online resource (2, vii, 68 p.)
Biosensors, Interfaces (Physical sciences), Biomolecules
The effect of temperature increase on the optical excitation of Surface Plasmon Resonance (SPR) at an Ag-Si metal-semiconductor (M-S) junction at a wavelength of 1 . 1 52 pm is investigated theoretically using computer modeling in Fortran. In order to accurately quantify the SPR, the temperature dependent optical constants for Ag and Si are obtained theoretically or semiempirically , using a Drude model for Ag and previous experimentally determined equations for Si (the behavior of the optical constants for crystalline Si and doped Si are found to have very little deviation between each other for our case). An improvement in the theoretical derivation for the optical constants of Ag is obtained, maintaining self-consistency. The optical constants are utilized to quantify the reflectance of an incident wave on an M-S junction, using Fresnel equations for a four layer system. The reflectivity of the M-S junction is indicative of the surface plasmon generation. There exists much industrial interest in increasing the amount of photocurrent generation in semiconductors for a given number of incident photons. This increase in photocurrent is often referred to as enhancing the quantum efficiency (Q). It has been previously shown by many groups that there can be an appreciable enhancement of Q due to the optical excitation of surface plasmons on a Schottky barrier junction (M-S junction), although all these previous studies were done at room temperature. Hence, the studies of temperature effect of SPR at the M-S junction could lead to interesting effects for the Q as well. In this thesis, we have studied qualitatively the effect of temperature increase on the optical excitation of SPR at an Ag-Si junction. From these results we have attempted to draw inference to the possibility of the enhancement of Q at elevated temperatures for such a diode junction.
Sanchez, Erik De Jesus, "Modeling of the Surface Plasmon Resonance (SPR) Effect for a Metal-Semiconductor (M-S) Junction at Elevated Temperatures" (1993). Dissertations and Theses. Paper 4624.